Rotary pump



F. EGERSDRFER ROTARY PUMP Filed June 2, 1925 Viulintenteld Apr. '-26, 1927. ,v

y Unten sra i,szaus 'rss PATENT. orifice.v

i m'rz nanasnnrrn, or omnorrmmnnc, ou r My invention relates to improvements in rotary pumps of the type comprising a vpair thereof in the bores of a solid block', the

l' trunnions or shafts of the gear wheels passing through bushings flliny out the annular spaces 4between the said trunnions .or

g shafts and the walls of the bores and being with their' inner end faces in close contact aor with the end faces of the gear wheels. Thereby the bearings provided by the bushings are in exact ai'gnment Pwith the gear wheels, so that no transverse` forces are exerted on the said gear .wheel's`.='-`Further, the bushings provide tight end walls forthe lsuction and pressure chambers of the pump.,y

1n the preferred construction the bores are of even diameter throughout the axial length of the pump casing, and the outer diameters of the gear wheelsy and the bushings are alike. The total length of each gear wheel and cooperating-bushings is equal to the axial length offthe' pump casing. Thereby I am ena led toft'nish the end faces of the pump casing and the bushings after assembling the said parts, which is important for insuring tight engagement between` the said parts, as

5oA from the gearwheels to opposite sides,l Fi 4,'1s a section taken on the of Fig. 3, and

will be explained hereinafter.

' For the purpose of explaining the invenm tion two examples embodying the same have been shown in the accompan ing drawing, in which the same reference c aracters have been used in all the views to indicate corresponding parts. in said drawing,

Fig. 1, is a sectional elevation showing a pum in which the gear wheels are pro vide at the ends of the shafts,

Fig. 2, is anend view looking from 'the left in Fig. 1 and with the head f f d Fig. 3, is a sectional elevation en a modification in which the shafts progect rig. 5,18 a dean View Showing las ings in whichthe shafts or trunnions of the gear wheels are mounted.

Application led :fune 2, 1925, Serial No.

Borana' Pour.

34,304, and in Germany Gctober 2, 1921.

ylin the example shown in Figs. 1 and 2 the pump comprises a casing a made from an integral 4blockand having two parallel bores b and'l the diameter of which is e ual 60 to the outer diameter of the gear whee s 0 and c1. At one of their end faces the said gear wheels are provided with 'trunniqns crshafts d and Z1 mounted in bushings e and e1. The said bushings till out the annular spaces-between theshafts d and d1 and. the walls of the bores of the pump casing and vprovide one of the end walls of the chambers enclosing the gear wheels. The

outer wall of the said chambers is provided 7@ by a head 'f bearing with its plane inner face on the plane end 'faces .of the ear wheels. The inner end faces-of the bushings and the inner face of the head f are 1n tight contact with the end faces of the gear wheels preventing any leakage of the liquid.

The gear wheel b is driven by a shaft g mounted in a head l and carrying a tlattrunnion h engaging in anaxial slot of the trunnion a?, a spring e' being located within the said 80 slot., A collar k formed on the shaft g bears on the end face of the bushing e and a conical end face provided at the opposite side of said collar is pressed bythe spring a' into engagement with aconical socket formed in the head Z thus providing a joint coniining the shaft g in a tight way. The head Z is formed with a cylindrical end providing a bearing for a gear wheel m formed with Ia slot engaged by a nose p of a dislr 'o se- 90 cured to the shaft g by means of a nut a. The gear wheel m is adapted for engagement with a gear-wheel (not shown) for imparting rotary movement to the shaft g, the shaft d and the gear wheels o and c1.

"The outer end face of the body a'closed by the head f is provided with grooves g and r covered bythe said head and providing'inleu;

. and outlet portsv for the pump, which ports.-

are located between the' end planes in the iii@ direction of the common tangent ofy the pitch lines of the gear wheels and therefore in the direction of the fiow of the liquid admitted to and dischar ed from ythe gear wheels. Thereby a smoot and unobstructed flow of the liquid is insured, and dead spaces are reduced to a minimum. .As appears from Fig. 2 'the grooves g and r may be very short, and they are connected with inlet and delivery passages u and 'v by ducts a and t. im

The ends of the grooves g and r are located a great distance away from the circumferits in a iarge tightening surface for the wheels being located substantially at middie of the body a2. Also in this case tie bushings fill out the annular spaces been the -trunnions and the walls of the or the casing, and they provide tight s 'tor the gear wheels and the trunnions. in axial here of the shaft d2 there is coiled spring i? which bears on the plane :.1 ti race oi the reduced Ailat end h2 of the g2 and presses the conical end face of 'he collar it into the conical socket of the ,d Z2. 7ihe inlet and outlet ports g2 and ases-ages a2 and o2. l hath eac i ples the bushings e, e1 and i constructed .in the manner shown inders, while the walls o' the 'ieri-ned with cut-out poracccmrnodating the non-reduced `ne end Ai'aces ont the gear e adjacent end 'faces o1? the the hea-d f, and by providing between the hushings and as or trunnions of the gear wheels age prevented, and b yieldingly ing` the i side avoided. By walls of the chambers enf the gear wheels of the iaces ot meinnch as ti e circumferential faces of the n is hincha or a2, and the end faces ,211, and separately iinishing the said corners Iare produced which eX- correspond to the sharp circumferendges of the gear wheels, thus insuring ontact between the said parts.

that the inner end faces of the bushe 'cv1 and the plate are in` close e end faces of the gear wheels ,ce respectively., so that there is s or the iiquid between the said To insure such close contact it L ianuiactnre the oump as i'ollows: t 'the Yhusiiings e2 and e'located at one ie oit the gear wheels are placed one beside e other on the grinding machine, and their are simultaneously tinished, so

ncaaiis the/end ieee or the body a, which n the modification shown in Figs. 3 andv ,are directly connected with the inlet and' cushings e By providing close gear wheeis c an c2 with the f ings e2 and c3 or the'end faces bushings e, el and the face of the mportant feature of' my invention re e8,- or the inner end .faces of the.

that both bushings have` exactly Athe same length.l In a similar Way the bushings e2, e3

located at the opposite side of the gear wheels, and thereafter the gear-wheels c2 and osare simultaneously finished, so that adjacent parts have exactly the same length.

Thereafter the said bush-ing and gear Wheels are assembled in the block'a1, whereupon the said block and bushings are simultaneously finished in the grinding machine. When now assembling the pump the total length "of the bushings and gear wheels is exactly -the same as the length of the block (1,2 taken in axial direction, and further the lengths ot adjacent arts are alike. Thus close contact between t e end faces of the ge'ar wheels and the adjacent end facesof the bushings is insured.

The pump is particularly adapted for feeding small and accurately measured amounts of liquids under pressure, for example for feeding viscous matter to the spinning nozzles in thel manufacture of artificial silk.

While in describing the invention reference has been made to two particular examples embodying the same l Wishit to be understood that my invention-is not limited to the constructions shown in the drawing, and that various changes may be made in the general arrangement of the apparatus and the' parts without departing construction oi' its from the invention.

ll claim: Y l. A pump comprising a solid formed with two parallel hores bounding each other and respectively having equal 'naar diameters throughout the length of said.'l block, interengaging gear wheels having their adjoining end faces flush with each other and having rejecting shafts, said gear wheels and shafts eing disposed within said hores, bushings illing out the spaces'between said shafts and the walls of said bores and engaging, with their inner end faces, the end "faces of said gear wheels .to the circumferences thereof, andmeans separate from said block for closing said bores at the ends opposite to said bushings, said means being in iid close contact with the end faces of said gear wheels to the circumferences thereof and with the adjacent parts of the Wall of said block, the casing provided by said block,

bushings, 'and closing means being formed with intake and delivery ducts.

2. A pump comprising a solid block hav- 712e ing plane arallel end faces and formed'with isa end faces, tothe circumferences thereof, the total axial length of each set'of bushings and gear wheels bein equal to the axial length of said block, and eads fixed to theend faces of said block,

the casing provided by said block, bushings and heads being formed with intake and de lively ducts.

3. A pump comprising va solid block formed with two parallel lbores bounding each other and respectively having equal diameters ,throughout the length of said block, interengaging gear wheels having their adjoining end faces flush with each respectively -dit) other and having shafts projecting from one of their end faces, sai

gear wheels and shafts being disposed Within the bores of said block and the .gear wheels having their end faces opposite to said shaftsflush wlth the adjacent end face lof said block, bushings filling out the spaces between said shafts andthe walls of said bores and engaging the inner end faces of said gear wheels to the circumferences thereof,- and a head fixed to the end posite to said shafts and in close contact with the adjacent end faces of said ear wheels, the casing provided bv said b ock and bushings being'and formed with intake and delivery ducts.

4. A pump comprising a solid block havi,

\intere ngaginr plane parallel end facesV formed with two parallel bores bounding each other and havin equal diameters throughout the lengt of said block, interengaging gear wheels having their adjoining ing end faces flush with each other and hav-y ing shafts projecting from one of theirend faces, said gear wheels and shafts being disposed within the bores of said block land the gear wheels having their. end faces oppo site to saidI shafts flush with the adjacent end face of said block, bushings filling out the spaces between said shafts and the walls of said bores and engaging the inner end faces vof said gear wheels to the circumferences thereof, and a head fixed to the end' face of said block opposite to said shafts and in close contact with the adjacent end faces of said gear wheels, the casing provided by said block. and .bushings being formed with intake and delivery ducts, the total axial length of each set of bushings and lengt of said block.

the end faces of said gearI wheels face of said blockl opar wheels being equal to the'axial 5. A pump comprising a formed with two paralle bores boundi each other and respectively having ual d1- ameters throughout the length of sai block, interengaging gear /wheels having their adjoining end faces flush with each other and provided with shafts projecting from one of the end faces of said gear wheels, said gear wheels andshafts being disposed within' the bores of said block and the gear wheels having their end faces opposite to said shafts lying Hush with the adjacent end face of said block, bushings filling out the spaces between said shafts and the walls of said bores and engaging the inner end faces of said gear Jwheels .to the circumferences thereof, and a head fixed to the end face of said block at the side opposite to said shafts and in close engagement with the adjacent end faces of said gear wheels,the total axial length of each set of bushings and gear wheels being equal to. the axial length of said block, the casing provided by said block, bushings, and closing means being formed with intake and dellvery ducts including, at their inner ends, grooves made in the end face of the block.

6'. A pump comprising a solid block formed with twn parallel bores .bounding each other and 'respectively having ual diameters throughout the length of said block, oear wheels havin their adjoining en aces flush with eac other and each having a projecting shaft, said gear wheels and shafts being disposed within said bores, bushings filling out the spaces between said shafts and the walls of said bores and engaging with their inner end faces the end faces of said gear wheels to the circumferences thereof, and means separate from said block for closing said bores attheend opposite to said bushings, said means being in close contact with the end Solid 'block faces of said gear wheels to the circumferences thereof and with the adjacent parts of the wall of said block, the casing provided by said block, bushings, and closing wheels.

In testimony whereof I hereunto aix my signature.

FRrz EGERSDRFER 

